i think kristam means to say her substrate is flourite, not flourish.
plants like fish take time to acclimate to tanks as well. i've had my 60 gal tank planted for a bit over 6 months now, it was a fresh setup, went through its algae fighting cycle for ages and has just come out of it for the most part. the plants were always struggling to hold on, leaves withering and browning.
i used root tabs in the substrate (i have just plain old play sand), and dose daily with the specified seachem flourish excel (co2 supplement). a few times a week approx, i dose with seachem flourish, flourish iron, flourish potassium and trace (for micro nutrients).
i didn't know how long my plants would last and kept it up. they started greening, the leaves thickened, stems are thick and rigid, and i'm even getting runners.
my amazon swords have grown runners on them, one is now almost halfway up the height of the plant at roughly 8 inches, and the other has grown all the way out of the top of my tank (24 inches tall) and is 3 inches out of said tank. all in the last week or two.
i'm using 2 48 inch double bulb shop lights from home depot, with philips plant and aquarium bulbs. cheap but seems to be doing the trick. they run from 6am to 6pm.
keep at it, and grab some of the plant nutrient products. i find that other than the co2, required are the trace, iron and potassium.